What is a head injury?
A head injury is any sort of injury to your brain, skull, or scalp. This can range from a mild bump or bruise to a traumatic brain injury. Common head injuries include concussions, skull fractures, and scalp wounds. The consequences and treatments vary greatly, depending on what caused your head injury and how severe it is.
Head injuries may be either closed or open. A closed head injury is any injury that doesn’t break your skull. An open (penetrating) head injury is one in which something breaks your scalp and skull and enters your brain.
It can be hard to assess how serious a head injury is just by looking. Some minor head injuries bleed a lot, while some major injuries don’t bleed at all. It’s important to treat all head injuries seriously and get them assessed by a doctor.
In general, head injuries can be divided into two categories based on what causes them. They can either be head injuries due to blows to the head or head injuries due to shaking.
Head injuries caused by shaking are most common in infants and small children, but they can occur any time you experience violent shaking.
Head injuries caused by a blow to the head are usually associated with:
- motor vehicle accidents
- falls
- physical assaults
- sports-related accidents
In most cases, your skull will protect your brain from serious harm. However, injuries severe enough to cause head injury can also be associated with injuries to the spine.
What are the major types of head injuries?
Hematoma
A hematoma is a collection, or clotting, of blood outside the blood vessels. It can be very serious if a hematoma occurs in the brain. The clotting can lead to pressure building up inside your skull. This can cause you to lose consciousness or result in permanent brain damage.
Hemorrhage
A hemorrhage is uncontrolled bleeding. There can be bleeding in the space around your brain, called subarachnoid hemorrhage, or bleeding within your brain tissue, called intracerebral hemorrhage.
Subarachnoid hemorrhages often cause headaches and vomiting. The severity of intracerebral hemorrhages depends on how much bleeding there is, but over time any amount of blood can cause pressure buildup.
Concussion
A concussion occurs when the impact on the head is severe enough to cause brain injury. It’s thought to be the result of the brain hitting against the hard walls of your skull or the forces of sudden acceleration and deceleration. Generally speaking, the loss of function associated with a concussion is temporary. However, repeated concussions can eventually lead to permanent damage.
Edema
Any brain injury can lead to edema, or swelling. Many injuries cause swelling of the surrounding tissues, but it’s more serious when it occurs in your brain. Your skull can’t stretch to accommodate the swelling. This leads to pressure buildup in your brain, causing your brain to press against your skull.
Skull fracture
The skull consists of 22 bones that come together via cranial sutures. The skull hardens and fuses through development to protect the brain. A skull fracture is any break in the cranial bones. There are many types of skull fractures, but only one major cause: an impact or a blow to the head that’s strong enough to break the bone. An injury to the brain can also accompany the fracture, but that’s not always the case. Learn more about skull fractures.
Diffuse axonal injury
A diffuse axonal injury (sheer injury) is an injury to the brain that doesn’t cause bleeding but does damage the brain cells. The damage to the brain cells results in them not being able to function. It can also result in swelling, causing more damage. Though it isn’t as outwardly visible as other forms of brain injury, a diffuse axonal injury is one of the most dangerous types of head injuries. It can lead to permanent brain damage and even death.
